ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 386 insertions, 0 deletions

diff --git a/net/mac80211/tests/elems.c b/net/mac80211/tests/elems.c
new file mode 100644
index 000000000..4b13a5aad
--- /dev/null
+++ b/net/mac80211/tests/elems.c
@@ -0,0 +1,386 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KUnit tests for element parsing
+ *
+ * Copyright (C) 2023-2025 Intel Corporation
+ */
+#include <kunit/test.h>
+#include "../ieee80211_i.h"
+
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+
+static const struct mesh_preq_parse_test_case {
+	const char *desc;
+	u8 len;
+	bool ae_enabled;
+	u8 target_count;
+	bool result;
+} mesh_preq_parse_cases[] = {
+	{
+		.desc = "shorter than header",
+		.len = 16,
+		.ae_enabled = false,
+		.target_count = 1,
+		.result = false,
+	},
+	{
+		.desc = "too short non AE, target count is not included",
+		.len = 29,
+		.ae_enabled = false,
+		.target_count = 1,
+		.result = false,
+	},
+	{
+		.desc = "too short non AE, target count is 1",
+		.len = 36,
+		.ae_enabled = false,
+		.target_count = 1,
+		.result = false,
+	},
+	{
+		.desc = "too short AE, target count is not included",
+		.len = 35,
+		.ae_enabled = true,
+		.target_count = 1,
+		.result = false,
+	},
+	{
+		.desc = "too short AE, target count is 1",
+		.len = 42,
+		.ae_enabled = true,
+		.target_count = 1,
+		.result = false,
+	},
+	{
+		.desc = "target count is zero",
+		.len = 26,
+		.ae_enabled = false,
+		.target_count = 0,
+		.result = false,
+	},
+	{
+		.desc = "target count is 21",
+		.len = 255,
+		.ae_enabled = false,
+		.target_count = 21,
+		.result = false,
+	},
+	{
+		.desc = "non AE, target count is 1",
+		.len = 37,
+		.ae_enabled = false,
+		.target_count = 1,
+		.result = true,
+	},
+	{
+		.desc = "non AE, target count is 20",
+		.len = 246,
+		.ae_enabled = false,
+		.target_count = 20,
+		.result = true,
+	},
+	{
+		.desc = "AE, target count is 1",
+		.len = 43,
+		.ae_enabled = true,
+		.target_count = 1,
+		.result = true,
+	},
+	{
+		.desc = "AE, target count is 20",
+		.len = 252,
+		.ae_enabled = true,
+		.target_count = 20,
+		.result = true,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(mesh_preq_parse, mesh_preq_parse_cases, desc);
+
+static const struct mesh_prep_parse_test_case {
+	const char *desc;
+	u8 len;
+	bool ae_enabled;
+	bool result;
+} mesh_prep_parse_cases[] = {
+	{
+		.desc = "shorter than header",
+		.len = 12,
+		.ae_enabled = false,
+		.result = false,
+	},
+	{
+		.desc = "non AE short",
+		.len = 30,
+		.ae_enabled = false,
+		.result = false,
+	},
+	{
+		.desc = "non AE",
+		.len = 31,
+		.ae_enabled = false,
+		.result = true,
+	},
+	{
+		.desc = "AE short",
+		.len = 36,
+		.ae_enabled = true,
+		.result = false,
+	},
+	{
+		.desc = "AE",
+		.len = 37,
+		.ae_enabled = true,
+		.result = true,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(mesh_prep_parse, mesh_prep_parse_cases, desc);
+
+static const struct mesh_perr_parse_test_case {
+	const char *desc;
+	u8 len;
+	u8 number_of_dst;
+	int ae_enabled_idx;
+	bool result;
+} mesh_perr_parse_cases[] = {
+	{
+		.desc = "shorter than header",
+		.len = 1,
+		.number_of_dst = 1,
+		.ae_enabled_idx = -1,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 0",
+		.len = 2,
+		.number_of_dst = 0,
+		.ae_enabled_idx = -1,
+		.result = true,
+	},
+	{
+		.desc = "number_of_dst is 20",
+		.len = 255,
+		.number_of_dst = 20,
+		.ae_enabled_idx = -1,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 1, non AE, short",
+		.len = 14,
+		.number_of_dst = 1,
+		.ae_enabled_idx = -1,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 1, non AE",
+		.len = 15,
+		.number_of_dst = 1,
+		.ae_enabled_idx = -1,
+		.result = true,
+	},
+	{
+		.desc = "number_of_dst is 1, non AE, extra short dst header",
+		.len = 25,
+		.number_of_dst = 1,
+		.ae_enabled_idx = -1,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 1, non AE, extra dst header",
+		.len = 26,
+		.number_of_dst = 1,
+		.ae_enabled_idx = -1,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 1, AE, short",
+		.len = 20,
+		.number_of_dst = 1,
+		.ae_enabled_idx = 0,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 1, AE",
+		.len = 21,
+		.number_of_dst = 1,
+		.ae_enabled_idx = 0,
+		.result = true,
+	},
+	{
+		.desc = "number_of_dst is 19, non AE, short",
+		.len = 2 + 13 * 19 - 1,
+		.number_of_dst = 19,
+		.ae_enabled_idx = -1,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 19, non AE",
+		.len = 2 + 13 * 19,
+		.number_of_dst = 19,
+		.ae_enabled_idx = -1,
+		.result = true,
+	},
+	{
+		.desc = "number_of_dst is 19, AE, short",
+		.len = 2 + 13 * 19 + 6 - 1,
+		.number_of_dst = 19,
+		.ae_enabled_idx = 18,
+		.result = false,
+	},
+	{
+		.desc = "number_of_dst is 19, AE",
+		.len = 2 + 13 * 19 + 6,
+		.number_of_dst = 19,
+		.ae_enabled_idx = 18,
+		.result = true,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(mesh_perr_parse, mesh_perr_parse_cases, desc);
+
+
+static void mle_defrag(struct kunit *test)
+{
+	struct ieee80211_elems_parse_params parse_params = {
+		.link_id = 12,
+		.from_ap = true,
+		.mode = IEEE80211_CONN_MODE_EHT,
+		/* type is not really relevant here */
+		.type = IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON,
+	};
+	struct ieee802_11_elems *parsed;
+	struct sk_buff *skb;
+	u8 *len_mle, *len_prof;
+	int i;
+
+	skb = alloc_skb(1024, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, skb);
+
+	if (skb_pad(skb, skb_tailroom(skb))) {
+		KUNIT_FAIL(test, "failed to pad skb");
+		return;
+	}
+
+	/* build a multi-link element */
+	skb_put_u8(skb, WLAN_EID_EXTENSION);
+	len_mle = skb_put(skb, 1);
+	skb_put_u8(skb, WLAN_EID_EXT_EHT_MULTI_LINK);
+
+	put_unaligned_le16(IEEE80211_ML_CONTROL_TYPE_BASIC,
+			   skb_put(skb, 2));
+	/* struct ieee80211_mle_basic_common_info */
+	skb_put_u8(skb, 7); /* includes len field */
+	skb_put_data(skb, "\x00\x00\x00\x00\x00\x00", ETH_ALEN); /* MLD addr */
+
+	/* with a STA profile inside */
+	skb_put_u8(skb, IEEE80211_MLE_SUBELEM_PER_STA_PROFILE);
+	len_prof = skb_put(skb, 1);
+	put_unaligned_le16(IEEE80211_MLE_STA_CONTROL_COMPLETE_PROFILE |
+			   parse_params.link_id,
+			   skb_put(skb, 2));
+	skb_put_u8(skb, 1); /* fake sta_info_len - includes itself */
+	/* put a bunch of useless elements into it */
+	for (i = 0; i < 20; i++) {
+		skb_put_u8(skb, WLAN_EID_SSID);
+		skb_put_u8(skb, 20);
+		skb_put(skb, 20);
+	}
+
+	/* fragment STA profile */
+	ieee80211_fragment_element(skb, len_prof,
+				   IEEE80211_MLE_SUBELEM_FRAGMENT);
+	/* fragment MLE */
+	ieee80211_fragment_element(skb, len_mle, WLAN_EID_FRAGMENT);
+
+	parse_params.start = skb->data;
+	parse_params.len = skb->len;
+	parsed = ieee802_11_parse_elems_full(&parse_params);
+	/* should return ERR_PTR or valid, not NULL */
+	KUNIT_EXPECT_NOT_NULL(test, parsed);
+
+	if (IS_ERR_OR_NULL(parsed))
+		goto free_skb;
+
+	KUNIT_EXPECT_NOT_NULL(test, parsed->ml_basic);
+	KUNIT_EXPECT_EQ(test,
+			parsed->ml_basic_len,
+			2 /* control */ +
+			7 /* common info */ +
+			2 /* sta profile element header */ +
+			3 /* sta profile header */ +
+			20 * 22 /* sta profile data */ +
+			2 /* sta profile fragment element */);
+	KUNIT_EXPECT_NOT_NULL(test, parsed->prof);
+	KUNIT_EXPECT_EQ(test,
+			parsed->sta_prof_len,
+			3 /* sta profile header */ +
+			20 * 22 /* sta profile data */);
+
+	kfree(parsed);
+free_skb:
+	kfree_skb(skb);
+}
+
+static void mesh_preq_parse(struct kunit *test)
+{
+	const struct mesh_preq_parse_test_case *params = test->param_value;
+	u8 data[64] = {};
+	struct ieee80211_mesh_hwmp_preq_top *top = (void *)data;
+	struct ieee80211_mesh_hwmp_preq_bottom *bottom;
+
+	top->flags = params->ae_enabled ? AE_F : 0;
+	bottom = ieee80211_mesh_hwmp_preq_get_bottom(data);
+	bottom->target_count = params->target_count;
+
+	KUNIT_EXPECT_EQ(test,
+			ieee80211_mesh_preq_size_ok(data, params->len),
+			params->result);
+}
+
+static void mesh_prep_parse(struct kunit *test)
+{
+	const struct mesh_prep_parse_test_case *params = test->param_value;
+	u8 data[64] = {};
+	struct ieee80211_mesh_hwmp_prep_top *top = (void *)data;
+	top->flags = params->ae_enabled ? AE_F : 0;
+
+	KUNIT_EXPECT_EQ(test,
+			ieee80211_mesh_prep_size_ok(data, params->len),
+			params->result);
+}
+
+static void mesh_perr_parse(struct kunit *test)
+{
+	const struct mesh_perr_parse_test_case *params = test->param_value;
+	u8 data[256] = {};
+	struct ieee80211_mesh_hwmp_perr *perr = (void *)data;
+
+	perr->number_of_dst = params->number_of_dst;
+	if (params->ae_enabled_idx > -1) {
+		struct ieee80211_mesh_hwmp_perr_dst *dst =
+			ieee80211_mesh_hwmp_perr_get_dst(
+				data, params->ae_enabled_idx);
+
+		dst->flags = AE_F;
+	}
+
+	KUNIT_EXPECT_EQ(test,
+			ieee80211_mesh_perr_size_ok(data, params->len),
+			params->result);
+}
+
+static struct kunit_case element_parsing_test_cases[] = {
+	KUNIT_CASE(mle_defrag),
+	KUNIT_CASE_PARAM(mesh_preq_parse, mesh_preq_parse_gen_params),
+	KUNIT_CASE_PARAM(mesh_prep_parse, mesh_prep_parse_gen_params),
+	KUNIT_CASE_PARAM(mesh_perr_parse, mesh_perr_parse_gen_params),
+	{}
+};
+
+static struct kunit_suite element_parsing = {
+	.name = "mac80211-element-parsing",
+	.test_cases = element_parsing_test_cases,
+};
+
+kunit_test_suite(element_parsing);